Manipulation of strain effect on optical anisotropy inself-assembled InGaAs quantum dots

摘要

Strain effect on optical anisotropy is studied by polarization analysis ofphotoluminescence from self-assembled InGaAs quantum dots embedded in wire (“monorail”)and freestanding wire (“air-bridge”) structures. Strong optical anisotropy is observed in thequantum dots embedded in monorails although such an anisotropy is absent in the as-growndots. The optical anisotropy is mainly attributed to strain asymmetry, which is consistent withthe observation of a doublet fine structure polarized parallel and perpendicular to the monorail.By changing the monorail into an air-bridge, the strain symmetry is partially restored, whichmanifests as a reduction of the optical anisotropy.